Hormonal Control of Water and Sodium in Plasma and Urine of Camels during Dehydration and Rehydration

Goumi, M. Ben; Riad, Fouad; Giry, J.; Farge, F. De La; Safwate, Abdallah; Davicco, Marie-Jeanne; Barlet, J.P.

doi:10.1006/gcen.1993.1045

Cited by 43 publications

(42 citation statements)

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“…However, in a similar study, 14 d of water deprivation stimulated a nearly 10-fold increase in PRA without the requisite increase in plasma aldosterone. The authors of that study suggest that the lack of increase in plasma aldosterone may be attributed to the hypernatremia also observed in these animals during the same period (Ben Goumi et al 1993), which is possible because treatment with the natriuretic furosemide alleviated the hypernatremia and resulted in an increase in PRA and concomitant increase in aldosterone (Riad et al 1994). Nonetheless, the existing data on RAAS and electrolyte balance in mammals adapted to prolonged periods of water deprivation suggest that discrepancies exist in the response of these animals to such an osmotic challenge.…”

Section: Discussionmentioning

confidence: 79%

“…An age-related change in the sensitivity of aldosterone response to fasting may be but one potential explanation for the discrepancy in the degree of change of aldosterone between pups and adults. Interestingly, aldosterone concentrations in hibernating marmots and waterdeprived camels remain below 100 pg/mL (Kastner et al 1978;Ben Goumi et al 1993), which is two-to 15-fold lower than concentrations observed in pinnipeds, providing an indication of aldosterone's importance in osmoregulation of marine mammals.…”

Section: Discussionmentioning

confidence: 82%

“…Serum osmolality and electrolyte concentrations in this study are similar to those measured in fasting seal pups (Costa and Ortiz 1982;Ortiz et al 1996Ortiz et al , 2000 and fasting lactating females (D. E. Crocker, unpublished data). In contrast, water deprivation for 10 or 14 d in camels increased mean plasma Na ϩ (3.3% or 24%, respectively) and osmolality (10.5% or 33.5%, respectively; Ben Goumi et al 1993;Yagil 1993), suggesting that camels exhibit signs of dehydration during their bouts of water deprivation, unlike elephant seals. Hibernating marmots have also been shown to increase mean plasma Na ϩ 3.4%-3.8% after 9 d (Zatzman and South 1972;Kastner et al 1978), further demonstrating the impressive feat by elephant seals of maintaining electrolyte homeostasis, especially in the face of increased activity levels observed in breeding adults.…”

Section: Discussionmentioning

confidence: 92%

“…For example, neurohypophyseal content of AVP in the hibernating garden dormouse (Eliomys quercinus) increased fourfold; however, AVP content remained unchanged in the hibernating mouse-eared bat (Myotis myotis; Hudson and Wang 1979). In water-deprived camels, plasma AVP increased 4.4-fold and sixfold after 10 and 14 d, respectively (Ben Goumi et al 1993;Yagil 1993). Only a few studies in pinnipeds have demonstrated an association between AVP (either infused as pitressin or quantified by changes in concentration) and reduced urine output or calculated free water clearance (Bradley et al 1954;Page et al 1954;Hong et al 1982;Ortiz et al 2002b).…”

Section: Discussionmentioning

confidence: 99%

“…Hibernators such as the American black bear (Ursus americanus; Brown et al 1971), the hedgehog (Erinaceus europaeus; Clausen and Storesund 1971), the little brown bat (Myotis lucifugus; Gustafson and Belt 1981), prairie dogs (Cynomys leucurus and Cynomys ludovicianus; Harlow and Braun 1995), and the yellow-bellied marmot (Marmota flaviventris; Kastner et al 1978) experience periods as long as 7 mo without food and water, but they are essentially metabolically inactive during this time. In contrast, camels (Camelus dromedarius) may withstand prolonged periods (2-3 wk) of food and water deprivation in arid and hot environments without exhibiting deleterious effects (Ben Goumi et al 1993;Yagil 1993). As with the aforementioned species, fasting for protracted periods (1-3 mo) is a natural component of the life-history year of the northern elephant seal (Mirounga angustirostris), occurring twice a year, regardless of age or sex (Le Boeuf et al 1972).…”

Section: Introductionmentioning

confidence: 99%

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Angiotensin II and Aldosterone Increase with Fasting in Breeding Adult Male Northern Elephant Seals (Mirounga angustirostris)

Ortiz¹,

Crocker²,

Houser³

et al. 2006

Physiological and Biochemical Zoology

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JSTOR is a not-for-profit service that helps scholars, researchers, and students discover, use, and build upon a wide range of content in a trusted digital archive. We use information technology and tools to increase productivity and facilitate new forms of scholarship. For more information about JSTOR, please contact support@jstor.org.. The University of Chicago Press ABSTRACTThe renin-angiotensin-aldosterone system (RAAS) appears to contribute significantly to osmoregulation of fasting northern elephant seal (Mirounga angustirostris) pups; however, RAAS has not been characterized in fasting adult seals. Therefore, this study examined the contribution of RAAS to water turnover rates in fasting adult male northern elephant seals. Blood samples were obtained twice during their breeding fast at an interval of 6.5 wk, and water efflux rate was estimated by isotopic dilution during the same period. Serum electrolytes (Na ϩ , K ϩ , Cl Ϫ ) and osmolality were unaltered between the two sampling periods, indicating ionic and osmotic homeostasis during the fast. Despite the lack of an increase in vasopressin, serum angiotensin II and aldosterone were increased and were significantly and positively correlated. Changes in aldosterone concentration and water efflux rate were significantly and negatively correlated, suggesting that the greater the increase in aldosterone, the smaller the loss of water. Adult male seals maintain ionic and osmotic homeostasis similar to that of fasting weaned pups, and this homeostasis appears to be mediated, at least in part, by RAAS, which probably contributes to increased water retention as well. The hormonal mechanisms by which northern elephant seals maintain water and electrolyte balance during fasting conditions appear to be similar regardless of age.

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Section: Discussionmentioning

confidence: 79%

Section: Discussionmentioning

confidence: 82%

Section: Discussionmentioning

confidence: 92%

Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Angiotensin II and Aldosterone Increase with Fasting in Breeding Adult Male Northern Elephant Seals (Mirounga angustirostris)

Ortiz¹,

Crocker²,

Houser³

et al. 2006

Physiological and Biochemical Zoology

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The origin of platyrrhines: An evaluation of the Antarctic scenario and the floating island model

Houle

1999

Am. J. Phys. Anthropol.

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This paper evaluates whether 1) protoplatyrrhines could have migrated to South America via Antarctica, and 2) the floating island model is a plausible transoceanic mode of dispersal for land vertebrates like protoplatyrrhines. Results show that Eocene Antarctica and Australia supported large and dense forests, and that the Antarctic fauna was comprised of many species of vertebrates, including placental and marsupial land mammals. However, no primate remains have ever been reported from these continents. Antarctica and South America were connected until the Middle Eocene (i.e., after the oldest Asian anthropoids), but two major water barriers existed between Antarctica and Asia since the Early Eocene. The Eocene and Oligocene water gap separating Africa and Antarctica was excessively large. Thus, all scenarios involving an Antarctic route have been rejected. The African scenario is difficult to falsify because only one water barrier existed, both paleowinds and paleocurrents were favorable, and Paleogene African anthropoids show phylogenetic affinities to platyrrhines. I tested whether a journey on a hypothetical floating island over the Paleogene Atlantic Ocean exceeds the survival limit of a genetically viable group of animals such as protoplatyrrhines. Studies of water deprivation suggest that they could have been able, with a body weight averaging 1 kg, to survive without water for at least 13 days. I have used the present Atlantic Ocean as a model for the velocity of Paleogene paleowinds and paleocurrents. Considering winds as the key accelerating force of floating islands, the Paleogene Atlantic water barrier could have been crossed, in the most conservative scenario, in 8 days at 50 Mya, 11 days at 40 Mya, and 15 days at 30 Mya. In order to survive a transoceanic journey, however, protoplatyrrhines had to be preadapted to strong seasonal variations in water availability in their original (African) environment. Once on the sea, their brains would have physiologically interpreted the rarity of water as the beginning of the dry season, and the group would have switched its diet to alternative foods, i.e., everything available on the floating island.

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Garlic prevents ultrastructural alterations caused by dehydration in mouse cerebral microvessels

Fahim

El‐Sabban

2001

Anat. Rec.

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Dehydration is known to significantly reduce both the time required for the first platelet aggregate and the time to full occlusion in photochemically-induced thrombosis, in vivo. Ultrastructural changes that contribute to such events remain unknown. Therefore, the effect of water deprivation for 24 hr, (as a model for dehydration) on the ultrastructure of mouse pial microvessels was investigated. The possible beneficial effect of garlic in preventing such ultrastructural changes was also investigated. Four groups of TO strain: control, control-garlic treated, dehydrated, and dehydrated-garlic treated male mice, 10/group, were used. Dehydration was induced by water deprivation for 24 hr. Garlic solution was i.p. injected at 0.1 ml/10g body weight. In urethane-anesthetized (2 mg/g, i.p.) mice, topical and transvessel bimodal fixation of pial microvessels was done with a phosphate buffered mixture of glutaraldehyde and paraformaldehyde, followed by a conventional electron microscopy procedure. Examination of control cerebral pial microvessels showed no evidence of cellular damage. Membranes of endothelial cells were intact. Within pial microvessels there was no evidence of platelet aggregation. Garlic treatments did not cause any ultrastructure abnormalities in control mice. Compared with control, dehydration caused the appearance of thrombi that consisted of platelet aggregates. Discoid platelets containing granules, spheroid degranulated platelets, and those with large pseudopodia were present in 80% of dehydrated mice. The venular endothelial surface of dehydrated mice revealed dilated profiles of endoplasmic reticulum and variously shaped vacuoles. Swelling of nuclear envelopes and mitochondrial distension were also present in dehydrated mice. Concomitant garlic treatment prevented most of these ultrastructural changes. These findings demonstrated the extent of damage to the pial microvessels in response to water deprivation and demonstrated the beneficial effect of garlic as a possible mean of protection against oncoming vascular pathology. Anat Rec 263: [85][86][87][88][89][90] 2001.

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Hormonal Control of Water and Sodium in Plasma and Urine of Camels during Dehydration and Rehydration

Cited by 43 publications

References 0 publications

Angiotensin II and Aldosterone Increase with Fasting in Breeding Adult Male Northern Elephant Seals (Mirounga angustirostris)

Angiotensin II and Aldosterone Increase with Fasting in Breeding Adult Male Northern Elephant Seals (Mirounga angustirostris)

The origin of platyrrhines: An evaluation of the Antarctic scenario and the floating island model

Garlic prevents ultrastructural alterations caused by dehydration in mouse cerebral microvessels

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